Means for assuring return movement of the keys of a piano action to their normal positions



A ril 1, 1969 N B'EEATON 1 3,435,720

- MEANS FON ASSUR'ING RISTURN MOVEMENT OF THE KEYS OF'A PIANO ACTION TO THEIR NORMAL POSITIONS Filed March 30. 1966 Sheet I of 2 I mvmon 5672 Z: [am

ATTORNEY April 1, 1969 EATON 3,435,720

MEANS FOR ASSURING RETURN MOVEMENT OF T X-IE KEYS OF A Filed March 30. 1966 PIANO ACTION TO THEIR NORMAL: POSITIONS Sheet of2 INVENT OR 3e Z. [ax/ ora flm ATTORNEY United States Patent MEANS FOR ASSURING RETURN MOVEMENT OF THE KEYS OF A PIANO ACTION TO THEIR NORMAL POSITIONS Ben E. Eaton, 93 Jackson Court, Hempstead, N.Y. 11550 Filed Mar. 30, 1966, Ser. No. 538,637 Int. Cl. Gc 3/18 US. Cl. 84-240 10 Claims ABSTRACT OF THE DISCLOSURE Means for relieving sluggishness of a piano action and to assure return movement of the keys to their normal positions comprising a strip of relatively soft, resilient material supported adjacent one of the movable components of the piano action in such manner that the strip of material is contiguous to the component when the component is in normal position, whereby when a key is depressed, a portion of the strip material is compressed, and upon release of the key the expansive force of the compressed material exerted on the movable component with which it is operatively associated returns the key to its normal position. The movable components of the piano action with which the strip material is associated are preferably the piano keys, butt members and hammershanks, or a combination thereof.

Heretofore, it has been suggested to relieve sluggish action and ease key return by applying a lubricating oil or solution tothe customary sources of such sluggishness, namely, the action centers and associated elements.

It has also been suggested to bias the keys to normal position by means of spring wires or the like, each of the wires having one end soldered or otherwise secured to the top of a balance rail pin, the opposite end portion of the wire being seated in a central groove formed in the top of the key, and extending rearwardly thereof.

While the above-noted methods no doubt function for their intended purposes, they are open to objection on the grounds that such methods are not economically feasible for use in minimizing or eliminating sluggishness of an entire action. In this connection, it will be appreciated that considerable time and expense would be involved in loosening, lubricating, and tightening flanges and re lated elements of the entire action; or to spring-bias each key thereof in accordance with heretofore suggested methods. Accordingly, these methods are generally used to ease or free a single key or a relatively few keys, which exhibit sluggishness or a tendency to stick.

There are several factors which, per se, interfere predominantly with the desired action of a single key or with a relatively few keys; usually the cause of such interference is easily determined by inspection and may be readily corrected. Among such factors are: faulty action centers, unequalized balance, humidity, ambient temperature variation over a relatively wide range, and the age of the piano.

In the event that sluggish action is due to a combination of the above-noted factors, diagnosis of the cause and identification of the precise factors responsible for the sluggishness is difiicult, if not impossible. A judgment with respect to the cause of the faulty action having been made, the return movement of the specific key or keys involved, is eased in accordance with the prior suggested methods.

After considerable research and experimentation, I have found that relief of faulty action, except in unusual cases, should not be confined to a single key or to a relatively few keys, because of potentially active factors havice ing the capacity of subsequently creating sluggish condish conditions throughout the entire action. Otherwise stated, I have found that corrective measures to alleviate sluggishness of certain keys should be accompanied by preventative measures with respect to the entire action, in order to assure desired return movement of all of the keys for a relatively long period of time.

The improved means for relieving sluggishness, and to assure desired return movement of the keys of a piano action, in accordance with the present invention, comprises essentially, a strip of soft and resilient polyurethane foam carried by a substantially rigid backing member adapted to be supported above the plane of the tops of the keys, and transversely thereof, in such manner that the bottom surface of the foam strip is contiguous to the top surface of each of the keys, when the keys are in their normal positions, whereby when a key is depressed the portion of the foam strip adjacent the top of the key is compressed, and upon release of the key the expansive force of the compressed foam exerted on the key returns it to normal position.

The present invention comprehends mounting the foam strip adjacent the butts to which the hammershanks of a vertical action are secured, or the strip may be supported above the hammershanks of a grand action in such fashion that the strip is compressed by the upward movement of a hammershank when a key is depressed. It is to be understood that the foam strips may be used in combination or separately, that is to say, the strip positioned above the plane of the tops of the keys, and in proximity thereto, may be employed in conjunction with a strip associated with a hammershank, or either of the arrangements may be used separately and depending upon the nature and degree of sluggishness involved.

An object of the invention is to provide improved means to assure return movement of the keys of a piano action to their normal positions.

Another object of the invention is to provide means adapted to relieve sluggishness and assure return movement of the keys of a piano action, said means incorporating a relatively soft, resilient strip of material constructed and arranged with respect to the piano action, whereby when a key is depressed a section of the strip is compressed, and upon release of the key the expansive force of the compressed material returns the key to normal position.

Still another object of the invention is to provide means to assure return movement of the keys of a piano action, said means incorporating a relatively soft, resilient strip of material constructed and arranged with respect to the plane of the tops of the keys when the keys are in their normal positons, whereby when a key is depressed the portion of the strip adjacent the key is compressed, and upon release of the key the expansive force of the compressed material exerted on the key returns it to normal position.

Yet another object of the invention is to provide means to assure return movement of the keys of a piano action, said means incorporating a plurality of relatively soft resilient strips of material constructed and arranged with respect to the keys and the hammershanks of a piano action, whereby when a key is depressed portions of the strips adjacent the key and its associated hammershank, respectively are compressed, and upon release of the key the expansive forces of the compressed portions of the strips exerted on the key and on its hammershank returns the key to its normal position.

A further object of the invention is to provide improved means to assure return movement of the keys of a piano action to their normal positions, said means being economical to manufacture and install; strong and rugged in construction; and not liable to get out of order even after long and continued use.

With these and other objects in view, which may be incident to my improvements, the invention consists in the parts and combinations to be hereinafter set forth and claimed, with the understanding that the several necessary elements, comprising my invention, may be varied in construction, proportions and arrangement, without departing from the spirit and scope of the appended claims.

In order to make my invention more clearly understood, I have shown in the accompanying drawings means for carrying the same into practical effect, without limiting the improvements in their useful applications to the particular constructions which, for the purpose of explanation, have been made the subject of illustration.

In the drawings:

FIGURE 1 is an elevational view of a section of a conventional vertical piano action incorporating the key return means of the present invention;

FIGURE 2 is a perspective view of a mounting bracket employed to support a strip of resilient foam material in the operative position with respect to the keys or other components of a piano action;

FIGURE 3 is a vertical sectional view along line 33 of FIGURE 2;

FIGURE 4 is a side elevational view of a modified mounting arrangement for supporting a strip of resilient foam material in the operative position with respect to the keys of a grand piano action;

FIGURE 5 is a sectional view along line 5-5 of FIG- URE 4;

FIGURE 6 is an elevational view of a section of a conventional grand piano action incorporating the key return means of the present invention;

FIGURE 7 is an enlarged detail view of the means employed to support a strip of resilient foam material on the hammershank flange of FIGURE 6;

FIGURE 8 is a sectional view along line 88 of FIG- URE 7; and

FIGURE 9 is a perspective view, partly in section, of the strip of foam material supported above a hammershank of the piano action shown in FIGURE 6.

Referring to the drawings, and more particularly to FIGURE 1, there is shown an elevational view of a portion of a conventional vertical piano action, partly in section, including a back rail 1, a key 2 connected by means of a capstan screw 3 to a wippen 4 pivotally connected as at 5, to the action rail 6 adapted to pivotally support a butt member 7 which carries a hammershank 8, having a hammer 9 secured thereto. A jack 10 is pivotally mounted on the wippen 4 by means of the jack flange 11, one end of the jack being secured to the butt member 7, the offset opposite end portion 12 of the jack having bearing engagement with the upper end of a jack spring 13; the opposite end of the spring resting on the upper surface of the wippen. A conventional butt spring, not shown, having one end secured to the spring rail 14 and its opposite end in seated engagement with the face portion of the butt member, may be employed, if desired.

It will be appreciated that the above description has been confined to the components of the illustrated piano action which are essential to a clear understanding of the function and operation of the key return arrangements of the present invention. In this connection, it will be understood that each key is supported intermediate its ends on a balance rail bearing so that when the exposed end portion of the key, not shown, is depressed, the opposite end portion of the key within the housing moves upwards, thus actuating the described components of the piano action, whereby the associated hammer strikes a string. It will be further understood that back and front rails, and the balance rail, as well as the spring rail and the action rail, extend transversely of the piano housing, that is to say, between the end walls of the housing.

Reference being had to FIGURES 2 and 3, the improved means for relieving sluggishness and to assure return movement of a piano action of the character illustrated in FIGURE 1, comprises a rigid, backing member 15 and a strip of soft and resilient plastic foam 16 secured thereto; the backing member is of channel shape, formed from light gauge metal, having a bottom flange 17, and depending side flanges 18, and the foam strip is preferably formed from polyurethane. The foam strip, which is of rectangular cross section, may be retained in seated position between the flanges 18 of the backing member by bending the free edge portions 19 of the flanges inwardly so as to clamp the strip therebetween.

The foam strip is supported in the operative position with respect to the keys or other movable components of a piano action by means of a pair of brackets, one of which is shown in FIGURE 2. Each of the brackets 20 comprises a channel-shaped arm 21 adapted to be secured to an end wall of a piano housing, said arm being arranged at right angles to an arm 22 slidably mounted on the flange 17 of the backing member by means of an elongated slot 23 and a bolt 24 having a portion of its threaded shank extending through the slot, the arm 22 being retained in desired adjusted position by a wing nut 25 threada-ble on the exposed shank portion of the bolt. The arm 21 of the bracket is secured to an end wall of the piano housing, designated generally by numeral 26, FIGURES 1 and 3, by means of screws 27 threadable through openings 28 into the end Wall.

Referring to FIGURES 4 and 5, there is shown a modified arrangement for supporting the foam strip in the operative position with respect to the plane of the tops of the keys of a grand piano action. In this embodiment of the invention, the backing member 29' and the polyurethane strip 16 are carried by spaced vertical members 30 adapted to be driven into the bottom frame 31 of the piano housing. Each of the members 30 is provided with a threaded portion 32, and the backing member and foam strip are formed with registering openings in the vicinity of their end portions adapted to receive the threaded portions 32 of the members 30. Vertical adjustment of the backing member and the foam strip is accomplished by pairs of threaded nuts 33 and 34, positioned on the members 30 above the backing member and below the foam strip, respectively. The position of the foam strip with respect to the keys is readily adjusted by turning the nuts 33 and 34 so as to move the backing and strip in the desired direction. It will be observed in the modified arrangement of FIGURE 4, that in one section thereof two of the compressed portions 35 above two of the keys, are shown in the dotted line positions which they assume when the exposed portions of the keys are depressed.

While the foam strip, as described hereinabove, is positioned contiguous the tops of the piano keys, it will be understood that the foam strip may be located adjacent other movable components of the piano action, for example, the butts 7, as shown in FIGURE 1, or the hammer shanks 8, FIGURE 6, as will be described more fully hereinafter. A strip of the foam may be employed with any one of the above-noted movable components, that is to say, with the keys, butts, or hamm'ershanks, or with combinations thereof, as illustrated in FIGURES 1 and 6.

It has been found that the present invention can also be employed to improve the touch of a piano action which is otherwise in acceptable, normal operating condition, that is, an action which does not involve sluggishness or delayed key return. In this connection, it will be appreciated that with professional pianists and teachers of piano, touch is one of the most important properties of a piano action. By means of the present invention, inrproved acceleration and repetition are obtained, and the touch can be adjusted or modified within a relatively wide range to meet the requirements of an individual pianist.

Referring to FIGURES 6-9, there is shown a modified foam strip designed for use with the hammershanks of a conventional grand piano action. An elevational view of a portion of a grand piano action, partly in section, as shown in FIGURE 6, includes a key 2 connected through the medium of a capstan screw 3 and a cushion member 36 to a support 37 pivotally mounted as at 38 on a flange 39 carried by the support rail 40; a balancer 41 is pivotally attached to a support top flange 42 as at 43, and a fly 30 having one end pivotally attached to the support 37, the opposite end of the fly being positioned so as to support the balancer in the vicinity of its end portion 44. A hammershank 8, having a hammer 9 secured thereto, is pivotally attached to a hammershank flange '45 as at 46, the hammershank knuckle 4 7 resting against the top surface of the balancer, when the key associated with the hammershank is in normal position.

The modified strip of foam 16', FIGURE 9, which is of equilateral trapezoidal shape in cross section, is supported above the plane of the top surfaces of the hammershanks, and transversely thereof by means of a backing member to which the foam strip is adhesively secured, said backing member being supported on the hammershank flange 45, FIGURE 6. It will be noted that the foam strip 16' is positioned on the backing member with its smaller base 48 in the vicinity of the free edge 49 of the backing member so that the strip tapers downwardly in the direction of its larger base 50, as viewed in FIGURE 6. By means of this arrangement, the foam is differentially compressed by the upward movement of the hammershank 8 when the key associated therewith is depressed, and upon release of the key, the expansive force of the compressed foam exerted of the hammershank returns it and the associated key to their normal positions.

If desired, a foam strip 16 of the character shown in FIGURES 2 and 3, may also be employed with the keys in conjunction with the strip 16' associated with the hammershanks, as illustrated in FIGURE 6. It will be further appreciated that a foam strip may be used with the abstract levers and wippens of a piano action to accelerate return of these components to normal positions. Additionally, the present invention may be employed in lieu of leveling leads currently used in connection with the regulating of touch resistance.

I claim:

1. In a piano action of the character described, including conventional front, back and balance rails; and sets of movable components such as keys, hammer butts, and hammer shanks; the improvement consisting of means for relieving sluggishness of the piano action and to assure return movement of the keys to their normal positions, said means comprising a strip of relatively soft, resilient material supported adjacent at least one set of the movable components of the piano action in such manner that the strip of material is contiguous to all of the movable components of the selected set when the said components are in their normal positions, whereby when a key is depressed a portion of the strip material contiguous to one of the movable components is compressed, and upon release of the key the expansive force of the compressed material exerted on the movable component returns the key to its normal position.

2. In a piano action having means for relieving sluggishness and to assure return movement of the keys to their normal positions, in accordance with claim 1, wherein the movable component is a key, and the strip of relatively soft, resilient material is supported above the plane of the tops of the keys and transversely thereof, between the balance rail and the back rail, in such manner that the strip is contiguous with the top of each key.

3. In a piano action having means for relieving sluggishness and to assure return movement of the keys to their normal positions, in accordance with claim 1, wherein the strip of relatively soft, resilient material is formed from polyurethane foam secured to a relatively rigid backing member.

4. In a piano action having means for relieving sluggishness and to assure return movement of the keys to their normal positions, in accordance with claim 1, wherein the movable component is a hammer butt, and the strip of relatively soft resilient material is supported in proximity to the hammer butts transversely thereof in such manner that the strip is contiguous to the inner face of each butt.

5. In a piano action having means for relieving sluggishness and to assure return movement of the keys to their normal positions, in accordance with claim 2, Wherein the strip of relatively soft, resilient material is secured to a rigid backing member supported on the piano housing by means of bracket members constructed and arranged for longitudinal adjustment with respect to the backing member.

6. In a piano action having means for relieving sluggishness and to assure return movement of the keys to their normal positions, in accordance with claim 2, wherein the strip of relatively soft, resilient material is formed from polyurethane foam secured to a rigid backing member, the backing member being supported on the piano housing in such manner that it is vertically adjustable with respect to the tops of the plane of the keys.

7. In a piano action having means for relieving sluggishness and to assure return movement of the keys to their normal positions, in accordance with claim 6, wherein the movable member is a hammershank, and the strip of polyurethane foam is supported above the plane of the upper surfaces of the hammershanks and transversely thereof in such manner that a portion of the strip is adjacent the upper surface of each hammershank when the hammershank is in normal position.

8. In a piano action having means for relieving sluggishness and to assure return movement of the keys to their normal positions, in accordance with claim 7, wherein the strip of polyurethane foam associated with the hammershanks is of trapezoidal shape in cross section, said strip being supported in such manner that the volume of compressed foam is progressively decreased.

9. In a piano action having means for relieving sluggishness and to assure return movement of the keys to their normal positions, in accordance with claim 1, Wherein the strip of relatively soft, resilient material is formed from polyurethane foam, one movable component of the piano action is a key and another movable component is a butt, and a strip of said foam is supported adjacent each of the movable components.

10. In a piano action having means for relieving sluggishness and to assure return movement of the keys to their normal positions, in accordance with claim 9, wherein one of the movable components is a key and another movable component is a hammershank.

References Cited UNITED STATES PATENTS 468,918 2/1892 Perry 84-243 2,455,139 11/1948 Prevost 84-240 2,594,967 4/1952 Miessner 84-240 RICHARD B. WILKINSON, Primary Examiner. LAWRENCE R. FRANKLIN, Assistant Examiner.

US. Cl. X.R. 84243 

